Preacher 4: Ancient History - Garth Ennis

While technically the fourth book in the Preacher series, Ancient History isn't part of the main Preacher story line and doesn't even use any of the main characters (Reverend Jesse Custer, his girlfriend, Tulip, and his vampire buddy Cassidy). Instead, this collection of side stories delves into the freakish, perverse, and downright mythic supporting characters. The main feature is the 106-page demonic Western featuring the "Saint of Killers.